1. Field of the Invention
This invention relates to a tremolo apparatus for an electric guitar, and particularly to a tremolo apparatus for an electric guitar equipped also with a tuning function.
2. Prior Art
It is generally known that when the tension of a string is lowered, the vibration frequency of the string is lowered, while on the contrary, when a string is tightened, vibration frequency of the string is increased. Accordingly, in an electric guitar, by causing a variation in string tension with quick repetitive cycles, the pitch (musical interval) is varied to high and low in order to obtain a specific sound effect; this is known as the so-called "tremolo effect."
A brief description will be given below of the structure of a solid type electric guitar having a conventional tremolo unit mechanism, with reference to FIGS. 1 and 2. In this electric guitar, reference numeral 1 denotes the body and reference numeral 2 denotes the neck. Over the body 1 and neck 2 a set of string 3 composed of, for example, six strings are disposed in a stretched form. One end of each of the strings 3 is held by a tuning peg 4 disposed at the head portion 2A of the neck 2 in such a manner that the strings 3 can be either tightened or loosened. The other ends of the respective strings 3 are held by a tremolo unit 5 provided on the body 1.
The above-mentioned tremolo unit 5 includes a bridge base 7, a plural number of bridge bodies 9, a balance spring 10, a tremolo arm 11, etc. The bridge base 7 is disposed on the body 1 in such a manner to be rotatable freely in a vertical direction by using a set screw 6 as the rotational fulcrum. The bridge bodies 9 are disposed on the bridge base 7 and correspond with the respective strings 3. Each of the bridge bodies 9 can be adjusted independently by an octave setting screw 8 by being moved in a longitudinal direction of the string 3. The balance spring 10 urges the bridge base 7 to turn clockwise in the FIG. 2. The tremolo arm 11 is used for moving the bridge base 7 up and down.
For stretching the strings 3, one end of the respective strings 3 are inserted from below into a through hole 13 of a spring anchoring portion 7a that is formed under the bridge base 7 so as to protrude from the underside of the bridge base 7. This spring anchoring portion 7a is positioned within a spring housing room 12 of the body 1 by being inserted into the same. The strings 3 inserted into the foregoing through hole 13 are then stretched along the upper surfaces of the corresponding bridge bodies 9. Thereafter, the strings 3 are anchored to and held by the tuning pegs 4, and a ball end portion 14 attached to the other end of the string 3 is anchored to the underside of the spring anchoring portion 7a.
After this operation, each string 3 is tuned to a specified pitch through adjustment effected by rotating the tuning peg 4. In this case, movement of the tremolo unit 5 in a counterclockwise direction by the sum total of the tensile force T.sub.1 of the strings 3 which are stretched to specified pitches is designed to be balanced at a certain point with the tensile force T.sub.2 due to the spring force of the balance spring 10, so that the bridge base 7 is held at an angle and position whereby the bridge base 7 is maintained in a state somewhat lifted from the body 1 as shown in the FIG. 2. In this state, when the tremolo arm 11 is moved vertically, the balanced state is put out of balance and the tension in each of the strings 3 is varied. As a result, the tremolo effect is obtained.
In the FIG. 1, reference numeral 17 indicates pick-up devices, and reference numerals 18 are the knobs for controlling sound volume and sound quality.
In such conventional tremolo unit mechanisms, however, the strings 3 must be inserted into the through hole 13 from the underside of the body 1 and then have to be led to the top surface of the bridge bodies 9. Therefore, the installation of the strings is troublesome posing a problem in handling.
Furthermore, conventional tremolo unit mechanisms, as mentioned above, have the following inconveniences: loosening of the strings 3 caused at the tuning pegs 4 and the pitches become deranged during operation of the tremolo mechanism.
In light of such problems, as shown in U.S. Pat. No. 4,171,661, a device to lock up the strings with a nut unit in order to prevent detune in pitch was provided. However, when using device provided by U.S. Pat. No. 4,171,661, once the string is locked by the nut unit, when the adjustment of the pitch becomes necessary thereafter, the lock must be released to adjust the pitch with the tuning peg, then the locking must be done again, thereby lowering operational efficiency.
As a result, a represented by UK Patent Application No. GB 2116 768 A, tremolo which are equipped with a fine tuning mechanism for pitch have been provided. In this device, the variable tuning range (a movable distance of the string in its stretching direction) is about 2 mm.